Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Previously known methods using ultrasound waves to acoustically confine or move an object are ineffective in moving or confining some objects. For instance, these methods are not well suited for moving or confining a large object, an object with a high mass density, or an object through which acoustic waves travel at a high rate of speed, such as a kidney stone.